1. Field of the Invention
The present invention relates to a method for manufacturing a substrate having a conductive pattern, and more specifically to a method of forming a conductive pattern through utilization of a concave-convex layer on a substrate.
2. Description of the Related Art
One method for forming a metal conductive pattern on the surface of a substrate is referred to herein as a “subtractive method”. In this method, a metal layer is provided on the substrate, a photoresist layer is laminated thereon, a resist pattern is formed by pattern exposing and developing, and then the resulting structure is etched. Difficulties with this process are twofold: Since most of the metal utilized is generally removed from the substrate, the metal must be recovered, and it is necessary to treat a large amount of etching effluent.
In another method, referred to here as “a full-additive method” a plating resist pattern is provided on a portion of a substrate, and a metal pattern is provided, by electroless plating, on the portion not coated with the plating resist pattern. Alternatively, there is a semi-additive method, a plating resist pattern is provided on a portion of a metal layer provided by electroless plating on a substrate or the like; and a metal pattern is then provided by electrolytic plating on the portion which is not coated with the plating resist pattern. Because a metal layer can be provided pattern-wise in both the full-additive method and semi-additive method, the drawbacks of the aforementioned subtractive method are eliminated.
However, in the full-additive method and the semi-additive method, although the metal pattern is determined by the shape of an opening portion of the plating resist pattern, the metal pattern grows by plating. Accordingly, it is difficult in these methods to form a square sectional shape and to obtain a constant line width.
In another method, disclosed in Japanese Patent Application Laid-Open (JP-A) No. 2000-265087, a pattern is printed by conductive ink on a transparent base material, coated with a negative type photoresist layer that is thicker than the pattern, exposed to light from the backside of the base material, developed to remove the photoresist layer on the pattern, and then a metal pattern is formed on the pattern by electrolytic plating. In this method, however, since the first pattern is formed by printing, it is difficult to secure dimensional accuracy and positional accuracy at a high level.